The invention relates to visible light reflecting particles for use in detergent compositions, to processes for making the particles and to detergent compositions comprising the particles.
In recent years, detergent manufacturers have introduced in their products small amounts of dyed particles or speckles. The particles can mask de-coloration in the product and/or allows the incorporation in the products of small amounts of ingredients which do not have the colour of the bulk of the product by masking this colour difference. Furthermore, it has been found that the detergent users associate products having dyed particles with improved cleaning that the consumer acceptance of product comprising coloured particles is normally higher than product not comprising such coloured particles.
These particles are often obtained by spraying-on an aqueous solution of a specific dye onto hygroscopic material and addition of these materials to the other ingredients, or directly onto the final detergent base particles and subsequently drying the thus dyed materials or particles. A problem associated with this method is that the hygroscopic material absorbs large amount of water which may result in caking of the product. This is particularly a problem when higher amounts of aqueous dye-solution need to be used, for example, when very diluted dye solutions are to be used, or strongly dyed particles are needed or the dye is absorbed by the material or particles which are to be dyed.
Another problem associated with detergents comprising large amounts of dye per particle can be that the dye can xe2x80x98bleedxe2x80x99 in the presence of water. This may be the case when the detergent is made by spraying on large amounts of aqueous dye solutions, or when the detergent comprises large amount of hygroscopic material or of course, when the detergents are introduced to the washing or cleaning liquid, This xe2x80x98bleedingxe2x80x99 may cause colour changes of the product and the packing material. Moreover, under certain conditions, the dye or the dye particles which may deposit on the fabrics, can xe2x80x98bleedxe2x80x99 on the fabrics and cause colour changes on the washed fabric.
Also, those particles which cause decolouration and require masking to not allows the presence of dye or sufficient amounts of dye.
However, despite these problems, it may be desirable to have some form of speckle particles present in the product to provide the required contrast in the product and/or masking of certain ingredients in the product.
The inventor has now found an improved method of providing the required masking of undesired coloration of detergent products. The inventor has now found that the same or a better masking or contrasting effect can be achieved when particles are incorporated in the product which reflect light, which can be achieved by providing particles which comprise or consist of a reflecting component. The presence of the specific light reflecting component then produces a certain light reflection by the particles containing the light reflecting component, which provides a contrast with the other ingredients of the products, or can mask the undesired colour of the particle containing the light reflecting component or of other ingredients of the product, thus resulting in an overall whiter or brighter product appearance. The light reflecting component can generally be used in very small quantities to provide the required effect
The use of the particles of the invention results in more formulation flexibility for the detergent manufacturer because the colour of the ingredients to be used is now less important. Also, any, often difficult, process steps to provide detergent ingredients of the required colour can now be dispensed of, for example one or more purification steps.
The particles of the invention can be used in addition to any dyed speckle, but they can also be used instead of any dyed speckle particles. The present invention even allows reduction or elimination of the use of dyed particles and thus the problems associated therewith. Thus, since the particles of the invention are able to provide the contrasting or masking when not coloured, these speckle particle may be useful in certain products in countries where the use of dyes in such products is not allowed.
The present invention provides a detergent particle comprising a visible light reflecting component and one or more particulate component which comprise one or more detergent ingredients, whereby the detergent particle exhibits a specular visible light reflection which is of higher intensity than the specular visible light reflection of the particulate component or components.
The reflecting detergent particles preferably has a lustre index, measured by a method described herein, which exceeds the lustre index of sodium citrate dihydrate sample, whereof 100% of the particles has a particle size of from 355 to 500 microns, having an mean particle size of 425 microns.
The reflecting particle preferably comprises the light reflecting component evenly applied on its surface.
The particle is useful for incorporation in laundry or dish washing compositions, fabric conditioning compositions or hard-surface cleaning compositions. In particular , solid compositions are envisaged herein, but the particles may also be useful in liquid compositions which allow the use of solid particles.
In another embodiment of the invention, a specific detergent composition is provided which comprise s a reflecting particle consisting of the specific light reflecting component.
Also provided are detergent tablets or bars comprising the reflecting component, in particular on the surface of the tablet or bar.
The reflecting component can be introduced in the detergent product by several methods. The inventor however has also found specific methods which are particularly effective. Hereby, a common detergent ingredient or commonly used solvent, such as water, is used to incorporate the light reflecting component into the detergent product. Thus, the invention also relates to processes for making the compositions and the particle and the use thereof.